Chop the beef and pork, mix, and add the bread of the 2 rolls, previously soaked in milk, 1 finely-chopped onion, 3 or 4 chopped anchovies, season with salt and pepper and bind with 2 eggs. Shape into rissoles, and fry lightly in butter. When done, put the Klops in a saucepan and cover with the sauce, made as follows: Melt the butter, mix with the flour and cook to a light yellow. Dilute with the stock and the white wine. Add the onion, the chopped anchovies, capers, mustard, sugar, peppercorns, salt and slices of lemon. Cook for 10 minutes, and pour over the Klops, cover the saucepan, and simmer for 2 minutes. Just before serving, add the yolks of 2 eggs mixed with a little melted butter.